What is an 2N3904 NPN Transistor : Specifications & Applications

• The 2N3904 is a common NPN bipolar junction transistor that is used for general-purpose low-power amplifying or switching. It is intended for low current and power, medium voltage, and moderately high speeds.
• A silicon NPN bipolar junction transistor (BJT) with a TO-92 packaging, the 2N3904 is typically employed for switching and amplification functions.

• Since it is an NPN transistor, electrons carrying negative charge are the main charge carriers.
• Base shifts from reverse to forward biased and begins conducting at a little voltage of about 0.7V.
• It is employed in a wide variety of devices, including televisions, household appliances, medium-load switches, and PWM applications.
• NPN transistors are those that have one p-type material sandwiched between two n-type materials. The NPN transistor amplifies the weak signal that enters the base and generates high-amplitude signals at the collector end.
• In an NPN transistor, an electron moves from the emitter to the collector region, causing current to flow through the transistor. This type of transistor is commonly used in circuits because its majority charge carriers are electrons, which have higher mobility than holes.

Pin Configuration of 2N3904 NPN Transistor

The pin diagram of the 2N3904 NPN transistor is shown below.

• Emitter – Current Drains out through emitter.
• Base – Controls the biasing of the transistor.
• Collector – Current flows in through the collector.

Features & Specifications of 2N3904 NPN Transistor

• Advanced process technology.
• Low error voltage.
• Quick switching times.
• Operation at full voltage.
• The capacity to handle large current and power loads.
• NPN transistor polarity.
• 60VDC is the collector-base voltage (VCBO).
• 40VDC is the Collector-Emitter Voltage (VCEO).
• (VEBO) Emitter-Base Voltage 6VDC.
• 200 mA is the continuous collector current (IC).
• (Cob)-4pF output capacitance.
• 300MHz is the transition frequency (fT).
• (hFE)-100-300 DC Current Gain.
• 55 to 150°C is the operating temperature range.
• 1.5W is the Power Dissipation (PD).

Applications of 2N3904 NPN Transistor

• Driver Modules like Relay Driver, LED driver, etc.
• Amplifier modules like Audio amplifiers, signal Amplifiers, etc.
• VCB and VBE are high and hence can be used to control voltage loads up to 40V.
• Commonly used in TV and other home appliances.